This invention was not made by an agency of the United States Government nor under contract with an agency of the United States Government.
The present invention relates to color measuring devices. It finds particular application in conjunction with devices for measuring colors produced by a liquid crystal display (xe2x80x9cLCDxe2x80x9d) monitor and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other like applications.
Colorimeters are known for measuring colors of a sample. One type of conventional colorimeter has been developed for measuring colors produced by a monitor (display). Two (2) common types of displays include, for example, cathode ray tube (xe2x80x9cCRTxe2x80x9d) monitors and liquid crystal display (xe2x80x9cLCDxe2x80x9d) monitors. Reasons for measuring colors displayed on a monitor include identifying actual colors being displayed and, optionally, comparing the actual displayed colors against standard accepted colors. One reason for making such a comparison is for modifying the displayed colors to more closely match the standard accepted colors (e.g., calibrating the monitor). For various reasons, monitors must be calibrated on a regular basis.
Until now, colorimeters have been designed to be used with CRT monitors. Because LCD monitors have several distinct characteristics compared to CRT monitors, colorimeters designed for use with CRT monitors do not always work well with LCD monitors. For example, LCD monitors noticeably change color with viewing angle. Furthermore, because LCD monitors include a soft viewing screen, colors displayed on the screen may change as a function of pressure applied to the screen. In fact, colors are often completely destroyed if too much pressure is applied to a soft viewing screen. It is to be understood that additional differences, which are not mentioned, exist between CRT and LCD monitors.
For the reasons discussed above, colorimeters designed for CRT monitors do not always work well for measuring colors produced by LCD monitors. Therefore, colorimeters designed for CRT monitors are not practical for calibrating LCD monitors.
The present invention provides a new and improved apparatus and method which addresses the above-referenced problems.
In one embodiment, a colorimeter for measuring a color of light includes a color sensing device, a hanging means, and a means for reducing color distortion. The hanging means hangs the color sensing device in an operative relationship relative to a color producing device. The means for reducing color distortion reduces color distortion on the color producing device while the color sensing device is in the operative relationship relative to the color producing device.
In one aspect, the hanging means includes a suspension device and a means for suspending the color sensing device from the suspension device.
In another aspect, the means for suspending includes a flexible material secured to the color sensing device and the suspension device.
In another aspect, the flexible material includes rubber.
In another aspect, the means for suspending further includes a dock. The flexible material is secured to the color sensing device via the dock. A counterweight is secured to the suspension device so that the counterweight balances the color sensing device, dock, and means for reducing color distortion.
In another aspect, a means substantially limits light received by the sensing device to be light emitted from the color producing device within a predetermined angle.
In another aspect, the means for substantially limiting light is a baffle.
In another aspect, the means for reducing color distortion includes a housing secured to the color sensing device. A flat surface on the housing contacts the color producing device. The flat surface substantially minimizes any pressure points on the color producing device.
In another embodiment, a colorimeter for measuring a color of light includes a color sensing device. A suspension device places the color sensing device in a first plane for operative relationship relative to a color producing device. A color distortion reduction device places the color sensing device in a second plane for operative relationship relative to the color producing device and substantially eliminates color distortion on the color producing device.
In another embodiment, a system for measuring a color of light includes a color producing device. A color detection device measures a color produced by the color producing device. A suspension device, secured to the color producing device, places the color sensing device in a substantially parallel plane for operative relationship relative to the color producing device. A color distortion reduction device places the color sensing device in a substantially perpendicular plane for operative relationship relative to the color producing device and substantially eliminates color distortion on the color producing device.
In another embodiment, a method for measuring a color of light includes placing a color sensing device in a substantially parallel plane for operative relationship relative to a color producing device. The color sensing device and a color distortion reduction device are placed in a substantially perpendicular plane for operative relationship relative to the color producing device. The color sensing device is secured to the color distortion reduction device, which substantially eliminates color distortion on the color producing device. Light is received from the color producing device in the color sensing device.